In the prior art, error detection and correction for semiconductor devices can be made by using identical semiconductor chips on a same printed wire board in which the identical semiconductor chips are connected together via the printed wires on the board. However the number of signals that can be compared (checked) is limited by the number of pins of the semiconductor chip. Therefore, there is a need for a semiconductor chip (and method for operating the same) in which the number of signals that can be compared is not limited by the number of the pins on the semiconductor chip.